In recent years, semiconductor light-emitting elements such as LED are used for lamps as highly efficient space-saving light sources. In particular, active research and development have been taking place on LED lamps using LEDs as the lighting replacing conventional fluorescent light and incandescent light bulb. For example, an LED lamp having the shape of light bulb (light bulb shaped LED lamp) has been proposed as lighting replacing the light bulb shaped fluorescent light and incandescent light bulb, and as lighting replacing the straight-tube fluorescent light, a straight-tube shaped LED lamp (straight-tube LED lamp) has been developed.
Examples of this type of LED lamps include a conventional light bulb shaped LED lamp disclosed in the patent literature 1, and conventional straight-tube LED lamp disclosed in the patent literature 2. LED modules each including a board on which LEDs are mounted are used for these LED lamps.